An example of an image forming device using an electrophotography system may be a copying machine, a printer, a facsimile. Each of these image forming devices forms an image on a sheet on the basis of image data inputted from peripheral devices for example.
In such a device, it may occur that an image is printed on a different position on the sheet from the original position of the image, i.e., the position of inputted image data. Such positional deviation of the image formed on the sheet results from a difference between (i) a position in which sheet carrying means carries the sheet and (ii) a position of an image written on an image holder (photoconductive drum) on the basis of the image data.
In order to correct the positional deviation, for example, the position in which the sheet is carried is adjusted, and a position in which the image is formed is adjusted to a predetermined position. In this manner, it is possible to perform adjustment so that the image is formed in a proper position of the sheet. Further, it is possible to adjust a position of the image formed on the image holder and a position of the sheet carried by sheet carrying means so that the one of the positions corresponds to the other.
For example, in an arrangement recited in Patent Document 1 (Japanese Unexamined Patent Publication No. 125314/1995 (Tokukaihei 7-125314) (Publication date: May 16, 1995)), reference image data stored in the image forming device in advance is outputted to the sheet, and the sheet is scanned by an image scanning device, so as to adjust the position of the image formed on the sheet.
Further, for example, in an arrangement recited in Patent Document 2 (Japanese Unexamined Patent Publication No. 186994/1998 (Tokukaihei 10-186994) (Publication date: Jul. 14, 1998)), first, an image that has not been subjected to adjustment is formed, and the image is confirmed by scanning means, so as to adjust the position of the image formed on the sheet.
Moreover, each of Patent Document 3 (Japanese Unexamined Patent Publication No. 265560/1996 (Tokukaihei 8-265560) (Publication date: Oct. 11, 1996)) and Patent Document 4 (Japanese Unexamined Patent Publication No. 69789/2003 (Tokukai 2003-69789) (Publication date: Mar. 7, 2003)) discloses an arrangement in which a test chart is used to perform the adjustment.
Recently, with diversification of image formation, multi-stage sheet containing means is often installed on the image forming device so as to efficiently use plural types of sheets. For example, Patent Document 5 (Japanese Unexamined Patent Publication No. 4493/1998 (Tokukaihei 10-4493) (Publication date: Jan. 16, 1998)) discloses an arrangement of a facsimile device provided with a plurality of feeding cassettes wherein a scanning position is adjusted for each cassette.
However, in the aforementioned conventional arrangements, a test chart or the like of a reference image is scanned by using the image scanning device which is a peripheral device, but it is necessary to provide an image scanning device which is properly adjusted and is free from any scanning deviation in order to exactly scan the positional deviation. Further, it is necessary to perform operations so many times in adjusting the image forming device. Such arrangement results in troublesome adjustment.
That is, in the conventional arrangements, the image formed on the sheet is confirmed through one's eyes for example, and a condition and an amount of the positional deviation are determined by the image scanning device, in order to properly figure out the positional deviation. Thus, when an image scanning device causing the scanning deviation is used, it is impossible to exactly figure out the positional deviation, so that it is impossible to perform the adjustment. Note that, such adjustment is performed by an assembling/adjusting caretaker or a service person at a time of production, or at a time when the service person places the image forming device, or at a time when parts or units concerning image formation are replaced with new ones.
For example, as to a multi-functional device (copying device) in which the image forming device and the image scanning device are combined, it is necessary to adjust the image scanning device with adjustment of the image formation in the multi-functional device. That is, in the image scanning device for inputting image data to the image forming device, when image data with the positional deviation is generated in scanning a document, the image data is inputted to the image forming device as it is. Thus, even the image forming device whose adjustment has been completed forms an image whose position is deviated. Note that, also the image forming device requires adjustment of the scanning position in this manner, so that the adjustment is performed by an assembling/adjusting caretaker or a service person.
Thus, in the multi-functional device for example, it is general that: a printed material (image-formed material: test chart) on which an image has been formed is scanned by the image scanning device on the basis of reference data, and a position and a scale factor of an image to be formed on a sheet in the image forming device are adjusted in accordance with thus scanned image. Therefore, in case where neither the image scanning device nor the image forming device have been adjusted, the image scanning device is previously adjusted, and the image forming device is adjusted thereafter, so as to adjust the multi-functional device.
In this case, the adjustment of the image scanning device requires a reference document (reference chart), so that a service person or the like has to always carry the reference chart. If he or she carries no reference chart, it is impossible to perform the adjustment.
In the conventional arrangements, the adjustment is performed in accordance with the following procedure. The test chart is scanned so as to adjust the image scanning device. After adjusting the image scanning device, the test chart is scanned again, and data of the scanned test chart is printed on a sheet by the image forming device. The sheet is scanned again so as to adjust the image forming device. In this manner, the adjustment operations are performed so many times, so that it takes great trouble to perform the adjustment.
Further, in case where a plurality of containing means for containing sheets are provided on the image forming device, a position and a scale factor of an image formed on the sheet are adjusted for each sheet containing means. However, it takes great trouble to perform the adjustment operations for each containing means.